The present invention generally relates to computer network systems; and more particularly, relates to establishing communication between a serial device and a device server.
Users of serial devices often have the need to remotely communicate with host computing systems (for example, a personal computer, a set top box, laptop computer, notebook computer or any other computing device, collectively referred to as a “PC” throughout this specification) to extend the distance between the devices and their hosts beyond that provided using, for example, an RS232 cable. The desired remote distance may span the length of an office building or even a continent.
Access to remote serial devices has been limited, since it was often necessary to physically connect a computer or PC to the serial device to download data from the serial device to the PC, or to provide for uploading data, operating parameters or software or firmware updates to the serial device from the PC. Fortunately, the advent of the Internet and network computing provided a method for providing remote communications. A demand arose to network enable older serial devices (may also be referred to as “legacy devices”) by creating products that have a serial port and an Ethernet port, and which can accept data from legacy devices and send the data over a network and/or the Internet. Legacy devices may include a stand-alone vending machine, a microwave, a dishwasher or any other device that has a controller or processor, even if the controller or processor is limited in its computing capability. Alternatively, legacy devices can include devices that have significant computing capabilities, such as a FAX machine, a copier, a printer and the like.
Today, the creation of device server technology in embedded systems allows users to place legacy serial devices onto Ethernet networks, and thus, the Internet, with minimal effort and with limited knowledge of networking on the part of the user.
Many consumer applications and legacy serial devices are designed to communicate via a local serial communication port (a “COM” port) to a PC through a wired connection, and thus are network incompatible. Information flow between the serial device and the PC is typically accomplished using the RS232 standard communication scheme. Thus, the only way to make a legacy serial device network compatible in the past required each serial device to be connected to a PC wherein information was communicated through the network to the PC, which then communicated the information to the serial device.
It is clear that a more cost effective approach would be to connect a legacy serial device to a device server that would then provide network connectivity to the serial device. Once such device is the xPico® and xPico® WiFi® embedded device server manufactured and distributed by Lantronix, Inc.
One problem is that different types of serial devices require different settings and configurations, which requires a way for the device server to be programmed to communicate with the legacy serial device. Thus, upon initially connecting a device server to a legacy serial device and powering up, an initial state of the serial device is unknown, as well as the data configuration needed for communication between the device server and the legacy device.
Therefore, there is a need for a device server which is essentially “teachable” such that the device server can communicate and exchange data with a wide variety of different legacy devices without requiring custom programming.